Scaffold platform elevator



Sept. 9, 1958 I o. E. MOYER 2,

SCAFVFOLDYLATFORM ELEVATOR Filed Sept; 27, 1957. s sheets-sheet 1 INVENTOR. 0,5 car- Mayer- BY BM,

H (9ft o rneys Sept, 9, 1958 o. E. MOYER 2,851,125

SCAFFOLD PLATFORM ELEVATOR Filed Sept. 27, 1957. 6 Sheets-Sheet 2 Fig. 4

INVENTOR. 05 E Mayer lisfittarnsys Sept. 9, 1958 o. E. MOYER' 2,851,125"

' SCAFFOLD PLATFORM EL VATOR-.- Filed Sept. 27, '1957 j "e sheets-sheet 3 Pig. 6

IN VEN TOR.

Oscar E. Mayer- Sept. 9, 1958 O. E- MQYER SCAFFOLD PLATFORM ELEVATOR Filed Sept. 27, 1957 6 Sheets-Sheet 4 INVENTOR.

. f-Mayer BYM Sept. 9, 1958 I o. E. MOYER 2,851,125

SCAFFOLD PLATFORM ELEVATOR Filed Sept. 27, 1957 6 Sheets-Sheet 5 x 22 m l3 0 a) I 13 a 45 o 43 a I 20 4 14 23 P 5 INVENTOR.

Sept. 9, 1958 o. MOY'ER 2,351,125

SCAFFOLD PLATFORM ELEVATOR s Sheets-Sheet 6 Filed Sept. 27, 1957 INVENTOR. 6"" E. Mayer BYMM,

SCAF F OLD ELATF-URM ELEVATOR Oscar E. Mayer, Zelienople, Pm, assignor to Universal Manufacturing Corporation, Zelienople, Pa, in corporation of Pennsylvania This invention relates to apparatus for raising and lowering platforms supported by scaffolds, and more particularly to a manually operated platform elevator.

It is common practice to erect a scaffold beside a wall that is being built up from bricks and to hang brackets on the scaffold in the space between it and the wall. Planks are laid across the brackets to form a platform for the mason to stand on. Another platform is laid in the scaffold at a higher level to support the bricks and other working materials. As the height of the wall increases, the platforms have to be dismantled and the brackets raised and attached to the scaffold at a higher level. The platform planks then have to be laid down again. All of this obviously consumes a considerable amount of time, which is especially costly in view of the high hourly wages that brick layers receive.

It is among the objects of this invention to provide a platform elevator that is readily attached to a scaffold, that can be moved up and down the scaffold without disconnecting the elevator from it, which can be operated by a man standing on the platform, and which requires no ropes or cables.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which Fig. 1 is a side view of my platform elevator connected to the end of a scaffold;

Fig. 2 is a fragmentary front view of the scaffold showing the elevator;

Fig. 3 is a plan view of the scafiold and the elevators at opposite ends of the working platform;

Fig. 4 is an enlarged side view of the elevator;

Figs. 5 and 6 are enlarged front and rear views, re-

spectively, of the elevator;

Fig. 7 is a plan view;

Fig. 8 is a fragmentary horizontal section taken on the line VIIIVIII of Fig. 4;

Fig. 9 is a fragmentary vertical section taken on the line IXIX of Fig. 4;

Fig. 10 is a rear view of the elevator as it is being raised;

Fig. 11 is a rear view of the elevator as it is being lowered;

Figs. 12 to 14 are schematic views illustrating upward movement of the elevator;

Figs. 15 and 16 are schematic views showing how the elevator is prepared for downward movement; and

Figs. 17 to 20 are schematic views depicting downward movement of the elevator.

Referring to Figs. 1, 2 and 3 of the drawings, a scaffold is erected in the usual way from prefabricated end panels 1 connected at the back by cross braces 2. Cross braces that would interfere with the elevators are omitted at the front of the scaffold, which is the side nearest the wall on which Work is being done. Each end panel consists of a pair of parallel legs 3 connected by vertically spaced horizontal braces 4. Supported by each of the end panels is one of my elevators 5. These elevators proiect from the front of the scaffold and support planks 6 Fatented Sept. 9, 1958 ice that form a working platform for the mason and other workers. As will be explained presently, the elevators can be moved up and down the scaffold to locate the platform at any desired level.

Each elevator includes a frame, shown best in Figs. 4 to 9, which may be constructed in various ways. The one shown has a pair of short upper horizontal supports 10 and a pair of longer lower horizontal supports 11. Each pair straddles the front leg of a scaffold end panel. The upper supports are rigidly connected in parallel relation by an angle bar 12 directly in front of the scaffold leg. Directly behind the ends of this bar, vertical angle bars 13 extend from the upper supports down to the top of a housing 14 mounted on the lower supports. At their rear ends the upper and lower horizontal supports are connected by vertical braces 16 and by angle bars 17 that approach close to the panel braces 4 so that the elevator cannot swing around the panel leg. Further angle bars 18 extend down beside the scaffold leg from the lower horizontal supports to a bottom angle bar 19, the ends of which are welded to curved braces 20 that extend from the rear ends of the lower supports to points adjacent their front ends. Pairs of concave rollers 22 and 23 engage opposite sides of the leg, the upper pair being journaled in bars 12 and 13, and the lower pair being journaled in bars 18 and 19. The lower supports project in front of housing 14 far enough to support planks 6 that form a working platform. Other planks 24- can be laid on the upper supports to form a platform for working materials. By having the upper planks rest on only the inner supports, they will not interfere with raising and lowering the elevators.

Rigidly mounted in the front of housing 14 and the upper part of a vertical plate 26 is a long horizontal bushing 27, in which a shaft 28 is journaled. The lower end of plate 26 is secured to the front part of a trough-shaped element 29 welded to the lower supports directly in front of the housing. Rigidly mounted on the outer end of shaft 28 is an upwardly extending handle 31. Secured to the rear end of this shaft inside the housing is a cross bar 32 that is horizontal when the handle is vertical. Pairs of links 33 and 34 are pivotally connected tothe opposite ends of this bar. This can be doneby securing the front end of a heavy pivot pin 36 in each end of the cross bar and pivotally suspending two links from the pin. As shown in Fig. 4, the lower ends of each pair of links are connected rigidly together by a heavy rod 37 extending through them and projecting from the lower end of the rear link 34.

Pivotally mounted on the rear end of each rod 37 is the central portion of a vertical hanger bar. The bars 41 and 42 have their lower ends pivotally and slidably mounted, by means of small rollers 43 (Fig. 6), in parallel vertical slots 44 in a pair of spaced plates 45 provided with forwardly extending side portions Welded to the lower vertical bars 18 of the frame. The hanger bars, of course, straddle the horizontal braces of the end panel. They also extend upward to points near the upper supports 10 and have their inner edges provided with vertically spaced inwardly projecting teeth 46. These teeth have inclined upper surfaces and slightly concave lower surfaces to hook over the top of one of the end panel braces. When the bars are hooked onto a brace in this manner, they support the frame from that brace. Due to the use of front and rear links to pivotally connect the hanger bars to the cross bar, greater strength and stability is provided. The concave rollers prevent the frame from tilting on the supporting leg.

With the construction described thus far, it will be seen that if the handle is swung from its upright or neutral position to one side, which, because 'of other elements that will be described presently, must be toward the right as viewed in Fig. 5, the cross bar 32 at the rear end of the shaft will have its left-hand end tilted up. This will raise hanger bar 41, as shown in Figs. and 13, while the elevator is supported from the scaffold by only hanger bar 42. Bar 41 can move upward because links 33 and 34 that connect it-to the-cross bar will permit the hanger bar to pivot on its lower end and allow the inclined upper surface of a tooth to ride up the adjoining end panel brace, as shown in dotted lines in Fig. 10. As soon as the point of the tooth reaches the top of the brace a coil spring 48, connecting the two front links 33, pulls the hanger bar back into hooking engagement with the brace. Consequently, the bar is hooked on the brace at a higher level than before.

When the handle is swung back to neutral position, the weight of the elevator will be supported by hanger bar 41 that was just raised, while the rising right-hand end of the cross bar will lift the other hanger bar 42 up a distance of one tooth, whereupon spring 48 will snap it into hooking engagement with the brace as shown in Fig. 14. Every time one end of the cross bar is raised, horizontal shaft 28 at its center will be raised half that distance, because the opposite end of the cross bar remains stationary. Due to the fact that the shaft is joined to the frame, the frame will be raised the same distance. Therefore, as the handle is swung from its central position to the right and back, the hanger bars climb up the end panel, and the frame travels up the adjoining leg.

The construction and operation just described that permits upward movement of the elevator is relatively simple as compared with what is required to lower it, because, before the elevator can be lowered, one or the other of the hanger bars has to be unhooked from the brace supporting it. This is accomplished by cams and springs. The cams 50 and 51 are mounted on the backs of vertical levers 52 and 53, respectively, pivotally suspended from pivots 54 projecting from the front of the housing on opposite sides of shaft 28. Extending lengthwise through trough 29 beneath the levers is a horizontal rod 56 that has its ends mounted in the opposite ends of the trough. Short spacing sleeves 57 are mounted on the end portions of the rod inside the trough, and the inner ends of the sleeves are normally engaged by square washers 58 slidably mounted on the rod. The washers are pushed against the sleeves, which serve as stops, by a coil spring 59 that also is slidably mounted on the rod. This spring is stronger than the spring 48 that pulls the links together. One of the washers engages the inner side of the lower end of lever 52, which is at the side of the shaft toward which the handle is swung to raise the elevator. other lever 53 projects between the other washer and the adjacent end of the trough and can swing back and forth. It is urged toward the right by a light coil spring 61 compressed between its upper part and a lug 62 on the front of the housing, although in some cases gravity may be all that is required.

Projecting forward from the lower ends of links 33 are kick out members, which may be in the form of parallel rods'65 and 66. They extend forward beside the cams on the levers. The right-hand rod 65 is always positioned for engagement with the outer side of cam 50, which is shaped so that when the rod is raised from neutral position it will ride up an upwardly and outwardly inclined cam surface. However, this rod is not raised from neutral position while the elevator is being raised, so lever 52 serves no purpose at such a time.

The other kick-out rod 66 normally is disposed at the inner side of the other cam 51, which is curved outwardly and upwardly, and therefore this rod likewise does not do anything beneficial to lever 53 when the rod is raised and lowered during raising of the elevator. On the other hand, when it is desired to lower the elevator, this rod and cam come into operation, but first the rod has to move around to the outside of the cam. This is accomplished by swinging the handle from neutral position to the left,

The

as shown in Fig. 15. That raises the housing 14 far enough to lift cam 51 above kick-out rod 66, so that when the handle is swung back to neutral the outside of the cam will slide down the rod and thereby swing the lever toward the other lever, as shown in Fig. 16. This compresses spring 59. During these operations, hanger bar 42 merely unhooks from the panel brace and then hooks the same tooth back over the brace, because lever 52 cannot swing to the right after the bar is unhooked and thereby swing the bar farther out to prevent it from rehooking in the same position.

When the handle then is swung a short distance to the right, as shown in Fig. 17, hanger bar 41 will be lifted far enough to slip off the panel brace, whereupon coil spring 59 will be allowed to expand and cause cam 51 to swing kick-out rod 66 to the left. That swings bar 41 far enough away from the brace to prevent it from catching on the brace until the handle has been swung to the left side to lower rod 66 relative to cam 51 so that spring 48 can pull the next higher tooth on the bar into engagement with the brace, as shown in Fig. 18. Of course, housing 14 and the elevator frame are lowered at the same time, so cam slides down stationary kick-out rod and swings lever 52 to the left to compress spring 59.

To unhook the other hanger bar 42 from the brace so that bar can be lowered next, the handle is swung a little farther to the left after bar 41 has hooked onto the brace. As the left-hand end of cross bar 32 therefore cannot tilt down any more, the right-hand end tilts up and unhooks bar 42 from the brace. As shown in Figs. 11 and 19, this allows spring 59 to expand and cause cam 50 to swing rod 65 to the right to swing the upper end of the hanger bar away from the brace and hold it there while it is being lowered one tooth as the handle is swung back toward neutral position. As rod 65 slides down cam 50, spring 48 is permitted to pull hanger bar 42 back into engagement with the brace, as shown in Fig. 20.

Lowering of the elevator can be continued by repeat ing the handle swinging movements depicted in Figs. 17 to 20. When it is desired to raise the elevator again, all the operator has to do is swing the handle to the right from neutral position. That will raise hangar bar 41 and slide kick-out rod 66 to the top of cam 51, whereupon spring 59 will expand and swing lever 53 to the left to the position shown in Fig. 13. The handle then is swung back and forth between its right-hand position and neutral until the elevator has climbed up the scaffold to the desired height.

One of the major advantages of this apparatus is that it requires no cables to lift the elevators. They are a nuisance and must be connected to the scaffold at some point. My elevators are absolutely safe, because they are hung from scaffold braces by toothed bars. When one bar is unhooked from a brace, the adjoining bar remains in engagement with the brace. The direction of movement of the elevators is controlled entirely by the direction in which the handle is swung. It is easy to attach these elevators to a scaffold, and they can be run up and down without having to be removed from the scaffold and then fastened to it again at a different level.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. The combination with a scaffold end panel having front and rear legs connected by vertically spaced horizontal braces, of a platform elevator comprising a frame straddling said front leg and movable up and down it as a track, the frame having a forwardly extending portion adapted to support a working platform, a horizontal shaft journaled in the frame in front of said leg and extending forward therefrom, a cross bar rigidly mounted on the rear end of the shaft, a pair of upright hanger bars disposed behind said leg on opposite sides of said braces and provided along their inner edges with vertically spaced teeth for hooking over one of said braces to support the hanger bars at a given level, pivot means slidably connecting the lower ends of the bars to the frame for vertical movement, links pivotally connecting the hanger bars with the ends of said cross bar on parallel horizontal axes to suspend the frame from the hanger bars, spring means urging the upper ends of the hanger bars toward each other, a pair of cam levers pivotally connected at their upper ends to the frame on parallel horizontal axes on opposite sides of said shaft, resilient means of greater power than said spring means urging the lower ends of said levers apart, a stop limiting outward movement of one end of said resilient means, cams on said levers, kick-out members secured to said links and extending forward therefrom, one of said members being located besidethe outer side of the cam nearest said stop, the other member normally being located beside the inner side of the other cam, and a handle on the front end of said shaft for turning it from a neutral position a predetermined distance in the direction of said stop to tilt up one end of the cross bar and thereby raise the adjoining hanger bar and the frame until the bar hooks over said brace at a higher level, whereby when the handle is swung back to neutral position the cross bar will be tilted in the opposite direction to again raise the frame and the other hanger bar until that bar hooks over said brace at a higher level, said other kick-out member being adapted to pass under said other cam to its outer side when the handle is swung from neutral position away from said stop, said other cam being formed to move the adjoining kick-out member outward to swing the associated hanger bar away from said brace when the handle is swung from neutral position slightly toward the stop, whereby when the handle is swung in the opposite direction the cross bar will be tilted to lower the frame and said associated bar until that bar hooks over said brace at a lower level, and the first cam being formed to move the adjoining kick-out member outward to swing the other hanger bar away from said brace when the handle is swung farther in said opposite direction so that the frame and bar can descend another bar tooth when the handle is swung back to neutral position again.

2. The combination with a scaffold end panel having front and rear legs connected by vertically spaced horizontal braces, of a platform elevator comprising a frame straddling said front leg and movable up and down it as a track, the frame having a forwardly extending portion adapted to support a working platform, a horizontal shaft journaled in the frame in front of said leg and extending forward therefrom, a cross bar rigidly rn-ountedon the rear end of the shaft, a pair of upright hanger bars disposed behind said leg on opposite sides of said braces and provided along their inner edges with vertically spaced teeth for hooking over one of said braces to support the. hanger bars at a given level, pivot means slidably connecting the lower ends of the bars to the frame for vertical movement, links pivotally connecting the hanger bars with the ends of said cross bar on parallel horizontal axes to suspend the frame from the hanger bars, spring means urging the upper ends of the hanger bars toward each other, and a handle on the front end of said shaft for turning it a predetermined distance in one direction to tilt up one end of the cross bar and thereby raise the adjoining hanger bar and the frame until the bar hooks over said brace at a higher level, whereby when the handle is swung back to its original position the cross bar will be tilted in the opposite direction to again raise the frame and the other hanger bar until that bar hooks over said brace at a higher level to support the frame while the frame and first-mentioned hanger bar are being raised again.

3; The combination with a scaffold end panel having front and rear legs connected by vertically spaced horizontal braces, of a platform elevator comprising a frame straddling said front leg and movable up and down it as a track, the frame having a forwardly extending portion adapted to support a working platform, a horizontal shaft journaled in the frame in front of said leg and extending forward therefrom, a cross bar rigidly mounted on the rear end of the shaft, a pair of upright hanger bars disposed behind said leg on opposite sides of said braces and provided along their inner edges with vertically spaced teeth for hooking over one of said braces to support the hanger bars at a given level, pivot means slidably connecting the lower ends of the bars to the frame for vertical movement, links pivotally connecting the hanger bars with the endsof said cross bar on parallel horizontal axes to suspend the frame from the hanger bars, spring means urging the upper ends of the hanger bars toward each other, a pair of cam levers pivotally connected at their upper ends to the frame on parallel horizontal axes on opposite sides of said shaft, resilient means of greater power than said spring means urging the lower ends of said levers apart, a stop limiting outward movement of one end of said resilient means cams on said levers, kick-out members secured to said links and extending forward into engagement with the outer sides of said cams, each of the cams being formed to move the adjoining kick-out member outward to unhook the associated hanger bar from said brace when that bar is raised slightly, and a handle on the front end of said shaft for turning it in a direction to unhook a bar and for turning the shaft in the opposite direction to lower the frame and the unhooked bar until that bar hooks over said brace at a lower level.

4. A platform elevator according to claim 3, in which each of said kick-out members is a horizontal rod in axial alignment with the pivotal connection between the link and hanger bar behind it. v

5. The combination with a scatford end panel having front and rear legs connected by vertically spaced horizontal braces, of a platform elevator comprising a frame straddling said front leg and movable up and down it as a track, the frame having a forwardly extending portion adapted to support a working platform, a horizontal shaft journaled in the frame in front of said leg and extending forward therefrom, a cross bar rigidly mounted on the rear end of the shaft, a pair of upright hanger bars disposed behind said leg on opposite sides of said braces and provided along their inner edges with vertically spaced teeth for hooking over one of said braces to support the hanger bars at a given level, pivot means slidably connecting the lower ends of the bars to the frame for vertical movement, links pivotally connecting the hanger bars with the ends of said cross bar on parallel horizontal axes to suspend the frame from the hanger bars, spring means urging the upper ends of the hanger bars toward each other, a pair of cam levers pivotally connected at their upper ends to the frame on parallel horizontal axes on opposite sides of said shaft, a horizontal rod mounted in the frame transversely thereof near the lower ends of said levers, a coil spring of greater power than said spring means slidably mounted on said rod and forcing the levers apart, a stop limiting outward movement of one end of the coil spring, cams on said levers, kick-out members secured to said links and extending forward into engagement with the outer sides of said cams, each of the cams being formed to swing the adjoining lever inward to compress the coil spring when the adjoining kick-out member is raised slightly, whereby the associated hanger bar will be unhooked from said brace and swung outward by the expanding coil spring, and a handle on the front end of said shaft for turning it in a direction away from said stop to raise a kick-out member and for turning the shaft in the opposite direction to lower the frame and said kick-out member and permit 1 8 the the unhooked bar to be swung by said spring means a common axis, and means parallel to said axis pivotally back into hookin'g engagement with said brace at a lower connecting the lower ends of both of said two links to the level.

6. A platform elevator according to claim 5, in which there are two of said links at each end of said cross bar 5 pivotally connected at their upper ends with that bar on No references cited.

hanger bar, behind'the'm. 

